Megalopal and first crab stages of Porcellanopagurus edwardsi Filhol, 1885(Crustacea : Decapoda : Anomura : Paguridea)

The megalopal and first crab stages of a hermit crab believed to be Porcell anopagurus edwaudsi Filhol, 1885, are described and illustrated from specim ens collected off New Zealand during the U.S. Antarctic Program, 1962-1968. This is the first report of post-larval development in the genus. While th e megalopal stage of P. edwardsi is generally quite similar to megalopae of other described pagurid genera, a significant difference is seen in the fi rst crab stage. At this stage in most pagurids there typically is reduction in the second pleopods on both sides of the abdomen; the remaining right s ide pleopods may be reduced or lost entirely, whereas left side pleopods us ually undergo only endopod reduction or loss. In contrast, all pleopods of P. edwardsi undergo dramatic reduction with the molt to the first crab stag e.